In certain applications, for example, aircraft landing gear, the main landing gear (MLG) and the nose landing gear (NLG) wheel and brake assembly is retained by an axle nut and a tang washer. Two cross bolts secure the axle nut to the axle after the required assembly torque is applied preventing the axle nut from coming loose. During MLG and NLG wheel and brake servicing, the tang washer is at risk of being omitted at reassembly. When omitted, the assembly can be loose, and can lack the proper bearing preload and can cause substantial damage to the wheel and brake assembly. In the worst case the wheel can separate from the airplane.
Some aircraft manufacturers have elected to simply use an axle nut, without a tang washer. However, this design solution has the following problems: Without the tang washer, the cross bolts that secure the axle nut after the proper preload torque has been applied are exposed to wheel bearing induced torque load. Cross bolts have been sheared in service, causing substantial damage and/or wheel departure.